package example.controller;

import java.io.IOException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;

public class UserAuthentication extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)
		throws IOException {
		UserService userService = UserServiceFactory.getUserService();
		
		String thisURL = request.getRequestURI();
		response.setContentType("text/html");
		if (request.getUserPrincipal() != null) {
			response.getWriter().println("<p>Hello, " +
                    request.getUserPrincipal().getName() +
                    "!  You can <a href=\"" +
                    userService.createLogoutURL(thisURL) +
                    "\">sign out</a>.</p>");
		} else {
			response.getWriter().println("<p>Please <a href=\"" +
                    userService.createLoginURL(thisURL) +
                    "\">sign in</a>.</p>");
		}
	}
}
